The present invention relates to a method for the reproduction of copyrighted print images on specialized print media and incorporating steganographic information.
Professional photographers traditionally charge for their services by requiring payment for the images provided to customers. The photographers maintain copyright ownership of the images and the customers are enjoined from creating copies of them. Additional copies must be purchased from the copyright owner, typically the photographer. However, the ready availability of digital imaging devices has made it relatively easy to create high-quality copies of copyrighted images without recourse or compensation to the copyright owners. In particular, color copiers, scanners, and home computers provide the means to create prints of copyrighted images. Moreover, digital image files can be readily copied by computers onto a variety of digital media.
Digital imaging equipment at retail, for example the Kodak Picture Maker Kiosk and high-quality photocopiers, as well as any digital professional photo-finishing laboratory with digital scanning equipment, can also be used to create very high-quality image copies. Current practice requires clerks to prevent such copying and also requires customers to indicate assent to a copyright clause when using the retail digital imaging equipment to create copies. Moreover, special photographic paper incorporating microscopic markers that are invisible to humans but that can be detected by scanners are used for printing copyrighted images. For example, U.S. Pat. No. 5,752,152 issued May 12, 1998 to Gasper et al. entitled Copy Restrictive System describes one such system using yellow microdots. Once the micro-dots are detected by a scanner, a suitably programmed digital reproduction device can interrupt the copying process. These techniques are known and widely used in the industry.
Steganographic techniques can be used in a similar way. By embedding information in a hard copy or digital image, a properly equipped digital imaging system can extract information from the image. This information can indicate whether or not an image is subject to copyright and interrupt the copying process as appropriate. U.S. Pat. No. 5,822,436 issued Oct. 13, 1998 to Rhoads entitled Photographic Products and Methods Employing Embedded Information describes such a process. Other techniques, such as pre-exposing photographic paper can also support this process.
Techniques also exist to locate copyrighted images and report their location to copyright owners. Such techniques rely on network-enabled software tools that access images over a network and analyze any images found. If images are located that contain the appropriate steganographic information, their location is reported. These techniques are effective for establishing ownership of copyrighted imagery and for preventing commercial copying.
However, the existing reproduction infrastructure does not support digital analysis methods in all cases and the cost of upgrading professional reproduction services is substantial. It is also true that not all copyright owners are willing to pay the additional costs of implementing a digital verification system. Moreover, some copyright owners are willing to allow reproduction of some copyrighted material but are unable to do so in a controlled manner. There is, therefore, a need for a method for the controlled reproduction of copyrighted prints that builds on existing industrial capabilities to add new capabilities but that are also compatible with existing practices.
This need is met according to the present invention by providing a method of controlling the reproduction of copyrighted images, that includes the steps of:
a) providing an image medium having a predetermined pattern of micro-dots;
b) steganographically embedding a reproduction authorization signal within some copyrighted digital images and not in others;
c) printing the copyrighted digital images on the image medium to produce copyrighted images;
d) in an image reproduction apparatus, attempting to detect the predetermined pattern of micro-dots and the authorization signal in an image to be reproduced;
e) if the authorization signal is detected, or the pattern of microdots is not detected, permitting reproduction of the image to be reproduced; and
f) if the authorization signal is not detected and the pattern of microdots is detected, preventing the reproduction of the image to be reproduced.